1. Field of the Invention
The invention relates in general to a portable electronic device, and more particularly to a portable electronic device measuring the length by rotating a roller.
2. Description of the Related Art
Living in today's society where science and technology advance rapidly, portable electronic devices have become indispensable to modern people in their everyday life. The mobile phone in particularity, with the features of slimness, light weight and portability, conveniently enables people to be connected whenever and wherever desired.
A conventional mobile phone at least includes a casing, a speaker and a volume dial. The speaker and the volume dial are both disposed on the surface of the casing. The speaker is for sending voices, and the volume dial is for a user to adjust the voice of the speaker.
However, when the user would like to measure the length of an object or a surface, the user might find it inconvenient if the user does not have a ruler or measuring tape at hand. Unfortunately, those who have a mobile phone at hand may not always bring a ruler or a measuring tape with them.